Sangster class May 3, 2022

 May 3, 2022

 

Telephone numbers

 

Toronto

 

416-395-2260 (school phone number)

Area code 416 (City of Toronto), 7 numbers follow the area code

 

416-AB5-2260 (first two numbers after area code cannot be 0 or 1)

- how many 416 numbers are there?

 

__8_, _8_, _10__, - _10__, _10__, _10_, _10__,

First two slots: 2,3,4,5,6,7,8,9 (eight possible numbers)

Third slot and on: 0,1,2,3,4,5,6,7,8,9

 

How many 416 numbers are there? 8x8x10x10x10x10x10 = 6400000 (6.4 million)

 

We ran out of 416 numbers about ten years ago

- land lines and cell phones (12 people in your class have more than 3 cell phones)

 

Solutions? Different area codes

905, 647, 298, 437 (newest)

 

The world has a new problem: running out of 3 digit area codes

 

Add another slot to the telephone number. Look at the telephone numbers for these countries

 

Iran: 10 digit phone numbers 98 (country code) -34567-89012

 

China: 12 digit phone numbers (most populated country in the world, 1.4 billion)

 

 

Brazil

 

Russia

 

India (second most populated country 1.1 billion)

 

Find how many area codes in Los Angeles, list them, find population in LA